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1、JAVA系统分析笔试题选择题1:public class xpublic object mobject o = new float;s:/line 3object oa = new object1;s:/line 4oa0 = o;s:/line 5o=null;s:/line 6return oa0;s:/line 7when is the float object, created in line 3,eligible for garbage collection?public class xpublic object mobject o = new float;s:/line 3obje
2、ct oa = new object1;s:/line 4oa0 = o;s:/line 5o=null;s:/line 6return oa0;s:/line 7when is the float object, created in line 3,eligible for garbage collection?after line 5.after line 6after line 7in this method2:use the operator“” and “”. which statement is true?0000 0000 0000 0000 0000 0000 0000 4 g
3、ive 0000 1010 0000 0000 00000000 0000 00000000 0000 0000 0000 0000 0000 0000 4 give 1111 1010 0000 0000 00000000 0000 00000000 0000 0000 0000 0000 0000 0000 4 give 0000 0000 0000 00000000 0000 0000 00000000 0000 0000 0000 0000 0000 0000 4 give 1111 1010 0000 00000000 0000 0000 00003:the following co
4、de is entire contents of a file called ,causes precisely one error during pilation:class subclass extends baseclassclass baseclassstring str;public baseclass;public baseclassstr=s;public class examplepublic void methodsubclass s=new subclass;baseclass b=new baseclass;which line would be cause the er
5、ror?the following code is entire contents of a file called ,causes precisely one error during pilation:class subclass extends baseclassclass baseclassstring str;public baseclass;public baseclassstr=s;public class examplepublic void methodsubclass s=new subclass;baseclass b=new baseclass;which line w
6、ould be cause the error?4:what will be the result of executing the following code?boolean a = true;boolean b = false;boolean c = true;ififif ;else ;else if ) ;else ;choices:what will be the result of executing the following code?boolean a = true;boolean b = false;boolean c = true;ififif ;else ;else
7、if ) ;else ;choices:code wont pileb. ”some things are true in this world”will be printedc. ”hey this wont pile” will be printedof these5:give the following java source fragement:s:/point xpublic class interestings:/do somethingwhich statement is correctly java syntax at point x?give the following ja
8、va source fragement:s:/point xpublic class interestings:/do somethingwhich statement is correctly java syntax at point x?class myclasss:/do other thingint pi=myclasss:/do something 6:public class parent int change class child extends parent which methods can be added into class child?int changeint c
9、hangint change7: 给出下面的代码片断。 。下面的哪些陈述为错误的 ?1) public void create 2) vector myvect;3) myvect = new vector;4) 给出下面的代码片断。 。下面的哪些陈述为错误的?1) public void create 2) vector myvect;3) myvect = new vector;4) a. 第二行的声明不会为变量myvect 分配内存空间。b. 第二行语句创建一个vector类对象。c. 第三行语句创建一个vector类对象。d. 第三行语句为一个vector类对象分配内存空间8:what
10、 is written to the standard output given the following statement:;select the right answer:9:which fragments are not correct in java source file?testpackage; public class tests:/do something.*; package testpackage; public class tests:/ do something. *; class persons:/ do something. public class tests
11、:/ dosomething.*; import *; public class tests:/ do something.10:give the following java class:public class examplestatic int x=new int15;public static void main;which statement is corrected?give the following java class:public class examplestatic int x=new int15;public static void main;which statem
12、ent is corrected?pile, some error will occur.run, some error will occur.is zero.is null.11: 使用 jdbc 可以做到的是a. 把二进制代码传送到任何关系数据库中b. 把 java 源代码传送到任何关系数据库中c. 把表单信息传送到任何关系数据库中d. 很容易地把 sql 语句传送到任何关系数据库中12:which method you define as the starting point of new thread in a class from which new the thread can b
13、e excution?void startvoid runvoid runnablestatic void main13:which statements about java code security are not true? bytecode verifier loads all classes needed for the execution of aprogram.code is performed by the runtime interpreter.runtimethe bytecodes are loaded,checked and run in an interpreter.class loader adds security by separating the namespaces for theclasses of the localfilesystem from t
